Handlify Accessors::FunctionGetArguments method.

R=yangguo@chromium.org

Review URL: https://codereview.chromium.org/19638003

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@15751 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

src/accessors.cc

@@ -576,6 +576,13 @@ const AccessorDescriptor Accessors::FunctionName = {
 //
 
 
+Handle<Object> Accessors::FunctionGetArguments(Handle<Object> object) {
+  Isolate* isolate = Isolate::Current();
+  CALL_HEAP_FUNCTION(
+      isolate, Accessors::FunctionGetArguments(*object, 0), Object);
+}
+
+
 static MaybeObject* ConstructArgumentsObjectForInlinedFunction(
     JavaScriptFrame* frame,
     Handle<JSFunction> inlined_function,

src/accessors.h

@@ -78,11 +78,11 @@ class Accessors : public AllStatic {
 
   // Accessor functions called directly from the runtime system.
   static Handle<Object> FunctionGetPrototype(Handle<Object> object);
+  static Handle<Object> FunctionGetArguments(Handle<Object> object);
 
   MUST_USE_RESULT static MaybeObject* FunctionSetPrototype(JSObject* object,
                                                       Object* value,
                                                       void*);
-  static MaybeObject* FunctionGetArguments(Object* object, void*);
 
   // Accessor infos.
   static Handle<AccessorInfo> MakeModuleExport(
@@ -90,10 +90,11 @@ class Accessors : public AllStatic {
 
  private:
   // Accessor functions only used through the descriptor.
+  static MaybeObject* FunctionGetPrototype(Object* object, void*);
   static MaybeObject* FunctionGetLength(Object* object, void*);
   static MaybeObject* FunctionGetName(Object* object, void*);
+  static MaybeObject* FunctionGetArguments(Object* object, void*);
   static MaybeObject* FunctionGetCaller(Object* object, void*);
-  static MaybeObject* FunctionGetPrototype(Object* object, void*);
   MUST_USE_RESULT static MaybeObject* ArraySetLength(JSObject* object,
                                                      Object* value, void*);
   static MaybeObject* ArrayGetLength(Object* object, void*);

src/deoptimizer.cc

@@ -1624,11 +1624,9 @@ void Deoptimizer::MaterializeHeapObjects(JavaScriptFrameIterator* it) {
         if (arguments.is_null()) {
           if (frame->has_adapted_arguments()) {
             // Use the arguments adapter frame we just built to materialize the
-            // arguments object. FunctionGetArguments can't throw an exception,
-            // so cast away the doubt with an assert.
-            arguments = Handle<JSObject>(JSObject::cast(
-                Accessors::FunctionGetArguments(*function,
-                                                NULL)->ToObjectUnchecked()));
+            // arguments object. FunctionGetArguments can't throw an exception.
+            arguments = Handle<JSObject>::cast(
+                Accessors::FunctionGetArguments(function));
             values.RewindBy(length);
           } else {
             // Construct an arguments object and copy the parameters to a newly

src/runtime.cc

@@ -12484,8 +12484,7 @@ RUNTIME_FUNCTION(MaybeObject*, Runtime_ClearStepping) {
 static Handle<JSObject> MaterializeArgumentsObject(
     Isolate* isolate,
     Handle<JSObject> target,
-    Handle<JSFunction> function,
-    FrameInspector* frame_inspector) {
+    Handle<JSFunction> function) {
   // Do not materialize the arguments object for eval or top-level code.
   // Skip if "arguments" is already taken.
   if (!function->shared()->is_function() ||
@@ -12493,10 +12492,9 @@ static Handle<JSObject> MaterializeArgumentsObject(
     return target;
   }
 
-  // FunctionGetArguments can't return a non-Object.
-  Handle<JSObject> arguments(JSObject::cast(
-      Accessors::FunctionGetArguments(frame_inspector->GetFunction(),
-                                      NULL)->ToObjectUnchecked()), isolate);
+  // FunctionGetArguments can't throw an exception.
+  Handle<JSObject> arguments = Handle<JSObject>::cast(
+      Accessors::FunctionGetArguments(function));
   SetProperty(isolate,
               target,
               isolate->factory()->arguments_string(),
@@ -12600,8 +12598,7 @@ RUNTIME_FUNCTION(MaybeObject*, Runtime_DebugEvaluate) {
       isolate, materialized, function, &frame_inspector);
   RETURN_IF_EMPTY_HANDLE(isolate, materialized);
 
-  materialized = MaterializeArgumentsObject(
-      isolate, materialized, function, &frame_inspector);
+  materialized = MaterializeArgumentsObject(isolate, materialized, function);
   RETURN_IF_EMPTY_HANDLE(isolate, materialized);
 
   // Add the materialized object in a with-scope to shadow the stack locals.